Helicopter rotor blades, in order to operate properly in the dynamic environment in which they are used, must be properly balanced so that they will not cause a high vibration level in the helicopter. The rotor blades are typically manufactured with a multi-component assemblage which includes a spar, a leading edge sheath, trailing edge pocket fairing, whose weight or mass can vary from blade to blade in what are intended to be identically balanced blades. The blade assemblage is typically manufactured by bonding the aforementioned components using layers of film adhesive. The use of such multiple components to form the rotor blades results in weight distribution variations from blade to blade. In order for the rotor blades to perform properly, the weight distribution and the resultant moments of the blade must meet predetermined criteria which define target weight distribution and moments along the length or span of the blade from root to tip, and also chordally or edgewise of the blade, from the leading edge to the trailing edge thereof. The desired moments can be defined as blade length weight ratios between the root end of the blade and the tip end of the blade at both the leading and trailing edges; and as blade chordal weight ratios at both the root end and the tip end of the blade. Achieving such predetermined weight distribution criteria will result in a "balanced" rotor blade that will operate properly in its intended environment. Thus, each rotor blade must be individually checked for weight distribution, and must be brought into "balance"; or stated another way, must be made to conform to the desired ideal weight distribution which will produce optimum root-to-tip blade moment, and leading edge-to-trailing edge blade moment, and thus proper operation of the rotor blades.
The aforesaid procedure is time-consuming as it requires two different balancing stations. It would be desirable to be able to balance the blade both spanwise and chordwise at a single balancing station using a single balancing procedure with the same equipment being used to determine both spanwise and chordwise moments in the blade.